Citrile

Citrile, in chemistry usually referred to as nitrile, denotes organic compounds that contain the nitrile group, a carbon triple-bonded to nitrogen (-C≡N). The nitrile group can act as a functional group in a molecule or serve as the defining feature of an entire compound class. IUPAC naming uses the suffix -nitrile for the parent compound (for example propionitrile) and the cyano prefix (cyano-) when the nitrile is a substituent.

Structure and properties: The cyano group is linear and highly polar, giving nitriles distinct reactivity compared with hydrocarbon fragments. Physical properties vary with substituents: many nitriles are liquids or solids at room temperature, and boiling points increase with molecular weight and polarity. Nitriles are generally stable but can participate in a range of transformations that make them versatile intermediates in organic synthesis. Safety considerations vary by compound; several nitriles are toxic or irritants and some can release hazardous hydrogen cyanide under strong hydrolysis conditions.

Occurrence and uses: Nitriles are produced commercially and occur as intermediates in the synthesis of carboxylic acids, amines, amides, and various polymers. The nitrile group is central to the production of acrylonitrile, a key monomer for polyacrylonitrile polymers used in fibers and plastics. Other common nitriles include acetonitrile and benzonitrile, which serve as solvents and building blocks in pharmaceutical and chemical industries.

Preparation and reactions: Nitriles can be prepared by substituting alkyl halides with cyanide sources, by dehydration of amides, or by dehydration of aldoximes derived from carbonyl compounds. They undergo hydrolysis to give carboxylic acids (or carboxylates) and can be reduced to primary amines. They also participate in cyanation reactions that form carbon–carbon bonds or cyanohydrin chemistry with carbonyl compounds.

Safety: Nitriles range in hazard, with some being highly toxic or volatile. Appropriate handling, ventilation, and protective equipment are important when working with nitriles.